LIST OF CONTENTS

GROWTH AND YIELD OF TOMATO AS INFLUENCED BY GA3AND PRUNING

MD. AL-AMIN JUEL Registration No.: 05-01627

MASTER OF SCIENCE IN

AGRONOMY

DEPARTMENT OF HORTICULTURE

SHER-E-BANGLA AGRICULTURAL UNIVERSITY DHAKA-1207

JUNE, 2011

GROWTH AND YIELD OF TOMATO AS INFLUENCED BY GA₃AND PRUNING

BY

MD. AL-AMIN JUEL

Registration No.: 05-01627 A Thesis

Submitted to the Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka,

in partial fulfillment of the requirements for the degree

of

MASTER OF SCIENCE (MS) IN

HORTICULTURE

SEMESTER: JANUARY- JUNE, 2011

Approved by:

..………... ...

Prof. Md. Hasanuzzaman Akand Prof. Dr. Md. Nazrul Islam

Dept. of Horticulture Dept. of Horticulture

SAU, Dhaka, SAU, Dhaka,

Supervisor Co-supervisor

Chairman,

Examination Committee

ACKNOWLEDGEMENTS

All praises to Almighty and Kindfull trust on to “Omnipotent Creator” for his never- ended blessing, it is a great pleasure to express profound thankfulness to my respected parents, who entiled much hardship inspiring for prosecuting my studies, thereby receiving proper education.

I would like to express my heartiest respect, my deep sense of gratitude and sincere, profound appreciation to my supervisor, Prof. Md. Hasanuzzaman Akand, Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka for his sincere guidance, scholastic supervision, constructive criticism and constant inspiration throughout the course and in preparation of the manuscript of the thesis.

I would like to express my heartiest respect and profound appreciation to my Co- supervisor, Prof. Dr. Md. Nazrul Islam, Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka for his utmost cooperation and constructive suggestions to conduct the research work as well as preparation of the thesis.

I express my sincere respect to the Chairman, Prof. Dr. Md. Ismail Hossain and all the teachers of Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka for providing the facilities to conduct the experiment and for their valuable advice and sympathetic consideration in connection with the study.

I would like to thank all of my roommates and friends who helped me in my research work and with technical support to prepare this thesis paper.

Mere diction is not enough to express my profound gratitude and deepest appreciation to my father, mother, brothers, sisters, and friends for their ever ending prayer, encouragement, sacrifice and dedicated efforts to educate me to this level.

June,2011 The Author

SAU, Dhaka

GROWTH AND YIELD OF TOMATO AS INFLUENCED BY GA₃AND PRUNING

BY

MD. AL-AMIN JUEL

Registration No.: 05-01627 A Thesis

Submitted to the Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka,

in partial fulfillment of the requirements for the degree

of

MASTER OF SCIENCE (MS) IN

HORTICULTURE

SEMESTER: JANUARY- JUNE, 2011

Approved by:

..………... ...

Prof. Md. Hasanuzzaman Akand Prof. Dr. Md. Nazrul Islam

Dept. of Horticulture Dept. of Horticulture

SAU, Dhaka, SAU, Dhaka,

Supervisor Co-supervisor

………..………

Prof. Dr. Md. Ismail Hossain Chairman,

Examination Committee

CHAPTER V

SUMMERY AND CONCLUSION

ACKNOWLEDGEMENTS

All praises to Almighty and Kindfull trust on to “Omnipotent Creator” for his never- ended blessing, it is a great pleasure to express profound thankfulness to my respected parents, who entiled much hardship inspiring for prosecuting my studies, thereby receiving proper education.

I would like to express my heartiest respect, my deep sense of gratitude and sincere, profound appreciation to my supervisor, Prof. Md. Hasanuzzaman Akand, Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka for his sincere guidance, scholastic supervision, constructive criticism and constant inspiration throughout the course and in preparation of the manuscript of the thesis.

I would like to express my heartiest respect and profound appreciation to my Co- supervisor, Prof. Dr. Md. Nazrul Islam, Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka for his utmost cooperation and constructive suggestions to conduct the research work as well as preparation of the thesis.

I express my sincere respect to the Chairman, Prof. Dr. Md. Ismail Hossain and all the teachers of Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka for providing the facilities to conduct the experiment and for their valuable advice and sympathetic consideration in connection with the study.

I would like to thank all of my roommates and friends who helped me in my research work and with technical support to prepare this thesis paper.

Mere diction is not enough to express my profound gratitude and deepest appreciation to my father, mother, brothers, sisters, and friends for their ever ending prayer, encouragement, sacrifice and dedicated efforts to educate me to this level.

June,2011 The Author SAU, Dhaka

CONTENTS

Chapter Title Page

1 INTRODUCTION 1

2 REVIEW OF LITERATURE 4

2.1 Effect of GA₃on growth and yield of tomato 4

2.2 Effect of pruning on growth and yield of tomato 10

3 MATERIALS AND METHOD 14

3.1 Location of the experimental field 14

3.2 Climate of the experimental area 15

3.3 Soil of the experimental field 15

3.4 Plant materials used 15

3.5 Raising of seedlings 15

3.6 Treatments of the experiment 16

3.7 Design of the experiment 16

3.8 Layout of the experiment 16

3.9 Cultivation procedure 17

3.9.1 Land preparation 17

3.9.2 Manuring and Fertilizing 17

3.9.3 Transplanting of seedlings 18

3.9.4 Intercultural operations 18

3.9.4.1 Gap filling 18

3.9.4.2 Weeding and mulching 18

3.9.4.3 Stalking and pruning 18

3.9.4.4 Irrigation 19

3.9.4.5 Plant protection 19

3.9.4.6 Harvesting 19

CONTENTS (Contd.)

Chapter Title Page

3.10 Parameters assessed 19

3.11 Data collection 20

i Plant height (cm) 20

ii Leaves per plant (no.) 21

iii Fruit clusters per plant (no.) 21

iv Flowers per Plant (no.) 21

v Fruits per Plant (no.) 21

vi Fruit length (cm) 21

vii Fruit diameter (cm) 21

viii Dry matter contentofleaves (%) 21

Ix Dry matter contentoffruit (%) 22

ix Yield per plot (kg) 22

x Yield per hectare (ton) 23

3.12 Statistical analysis 23

4 RESULTS AND DISCUSSION 24

4.1 Plant height (cm) 24

4.2 Leaves per plant 26

4. 3 Branches per plant 29

4.4 Fruit clusters per plant 30

4. 5 Flowers per Plant 31

4. 6 Fruits per Plant 31

4. 7 Fruit length (cm) 32

4. 9 Dry matter content of leaves (%) 35

4. 10 Dry matter content of fruit (%) 36

4.11 Yield per plot (kg) 36

4.12 Yield per hectare (ton) 37

5 SUMMARY AND CONCLUSION 38

6 REFERENCES 42

LIST OF TABLES

Number Title Page

01 Combined effect of GA₃ and pruning on different

plant characteristics of tomato 29

02 Effect of GA₃ and pruning on different yield

contributing characteristics of tomato 33 03 Combined effect of GA₃ on different yield

contributing characteristics of tomato 34 04 Effect of GA₃ and pruning on different yield

contributing characteristics of tomato 38 05 Combined effect of GA₃ and pruning on different

yield contributing characteristics of tomato 39

LIST OF FIGURES

Number Title Page

01 Effect of GA₃ on plant height of tomato 25

02 Effect of pruning on plant height of tomato 26

03 Effect of GA₃ on leaves/plant of tomato 27

04 Effect of pruning on leaves/plant of tomato 28

LIST OF APPENDICES

Number Title Page

I Monthly records of air temperature, relative humidity, rainfall and sunshine during the period

from October 2010 to April 2011 48

II The physical and chemical characteristics of soil (0 - 15 cm depth) of the experimental site as

observed prior to experimentation. 48

III Analysis of variance of the data for different plant

characteristics 49

IV Analysis of variance of the data for different yield

contributingcharacteristics 49

LIST OF ABBREVIATION AND ACRONYMS

AEZ = Agro-Ecological Zone

BARI = Bangladesh Agricultural Research Institute HRC = Horticulture Research Centre

BBS = Bangladesh Bureau of Statistics FAO = Food and Agricultural Organization

et al. = And others

TSP = Triple Super Phosphate

MOP = Murate of Potash

RCBD = Randomized complete block design

DAT = Days after Transplanting

ha^-1 = Per hectare

g = gram (s)

kg = Kilogram

SAU = Sher-e-Bangla Agricultural University SRDI = Soil Resources and Development Institute

wt = Weight

LSD = Least Significant Difference

0C = Degree Celsius

NS = Not significant

Max = Maximum

Min = Minimum

% = Percent

NPK = Nitrogen, Phosphorus and Potassium CV% = Percentage of coefficient of variance

DEPARTMENT OF HORTICULTURE

Sher-e-Bangla Agricultural University

Sher-e-Bangla Nagar, Dhaka-1207

Memo No: SAU/HORT/... Date: ...

CERTIFICATE

This is to certify that the thesis entitled “Growth and Yield of Tomato as Influenced by GA₃ and Pruning”submitted to the Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka, in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in HORTICULTURE, embodies the result of a piece of bona fide research work carried out by MD.

AL-AMIN JUEL, Registration No.: 05-01627 under my supervision and guidance. No part of the thesis has been submitted for any other degree or diploma.

I further certify that such help or source of information, as has been availed of during the course of this investigation has been duly acknowledged.

Dated: June, 2011

Dhaka, Bangladesh Prof. Md. Hasanuzzaman Akand Department of Horticulture Sher-e-Bangla Agricultural University

Dhaka-1207 Supervisor

GROWTH AND YIELD OF TOMATO AS INFLUENCED BY GA₃AND PRUNING

By

MD. AL-AMIN JUEL

ABSTRACT

An experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Dhaka during the period from October 2010 to March 2011 to find out the effect of GA3and pruning on the growth and yield of tomato. The experiment consisted of three doses of GA3 such as 80, 100 and 120 ppm with control; three different pruning levels such as 1, 2 and 3 stem pruning. The experiment was laid out in a RCBD with three replications. Both GA3 and pruning had significant influence on growth and yield contributing characters of tomato. At 75 DAT, the highest plant height (117.30cm), maximum number of leaves/plant (75.30) and highest yield (29.03 t/ha) were recorded from GA3 spray at 120 ppm. At 75 DAT, the highest plant height (113.60 cm), maximum leaves per plant (67.00) and yield (28.11 t/ha) were recorded from 2 stem pruning. The combined effect of 120 ppm GA₃ and 2 stem pruning performed the highest yield (31.89 t/ha) and lowest from G₀P₁.So,120 ppm GA₃with 2 stem pruningmay be used for higher yield of tomato.

TABLE OF CONTENTS

Chapter Title Page

ACKNOWLEDGEMENTS i

ABSTRACT ii

TABLE OF CONTENTS iii

LIST OF TABLES v

LIST OF FIGURES vi

LIST OF APPENDICES vii

LIST OF ABBREVIATED TERMS viii

I INTRODUCTION 1

II REVIEW OF LITERATURE 4

2.1 Literature on GA₃ 4

2.2 Literature on pruning 10

III MATERIALS AND METHOD 14

3.1 Location of the experimental field 14

3.2 Climate of the experimental area 14

3.3 Soil of the experimental field 16

3.4 Plant materials used 16

3.5 Raising of seedlings 16

3.6 Treatments of the experiment 17

3.7 Design of the experiment 17

3.8 Layout of the experiment 17

3.9 Cultivation procedure 18

3.9.1 Land preparation 18

3.9.2 Manuring and fertilizing 18

3.9.3 Transplanting of seedlings 19

3.9.4 Preparation of GA₃ 19

3.9.5 Intercultural operations 19

3.9.5.1 Gap filling 19

3.9.5.2 Weeding and mulching 20

3.9.5.3 Stalking and pruning 20

3.9.5.5 Irrigation 20

3.9.5.6 Plant protection 20

3.9.5.7 Harvesting 21

3.10 Parameters assessed 21

3.11 Data collection 21

i Plant height 21

ii Leaves per plant 22

iii Fruit clusters per plant 22

iv Flowers per plant 22

v Fruits per plant 22

vi Fruit length 22

vii Fruit diameter 23

viii Dry matter content of leaves 23

ix Dry matter content of fruit 23

x Yield per plot 24

xi Yield per hectare 24

3.12 Statistical analysis 24

IV RESULTS AND DISCUSSION 25

4.1 Plant height 25

4.2 Leaves per plant 27

4. 3 Branches per plant 30

4.4 Fruit clusters per plant 31

4. 5 Flowers per plant 32

4. 6 Fruits per plant 32

4. 7 Fruit length 33

4. 8 Fruit diameter 35

4. 9 Dry matter content of leaves 36

4. 10 Dry matter content of fruit 36

4.11 Yield per plot 37

4.12 Yield per hectare 38

V SUMMARY AND CONCLUSION 40

VI REFERENCES 44 LIST OF TABLES

Number Title Page

01 Combined effect of GA₃ and pruning on

different plant characteristics of tomato 30 02 Effect of GA₃ and pruning on different yield

contributing characteristics of tomato 34 03 Combined effect of GA₃ on different yield

contributing characteristics of tomato 35 04 Effect of GA₃ and pruning on different yield

contributing characteristics of tomato 39 05 Combined effect of GA₃ and pruning on

different yield contributing characteristics of

tomato 39

LIST OF FIGURES

Number Title Page

01 Effect of GA₃ on plant height of tomato 26

02 Effect of pruning on plant height of tomato 27

03 Effect of GA₃ on leaves/plant of tomato 28

04 Effect of pruning on leaves/plant of tomato 29

LIST OF APPENDICES

Number Title Page

I Monthly records of air temperature, relative humidity, rainfall and sunshine during the period

from October 2010 to April 2011 50

II The physical and chemical characteristics of soil (0 - 15 cm depth) of the experimental site as

observed prior to experimentation. 50

III Analysis of variance of the data for different

plant characteristics 51

IV Analysis of variance of the data for different yield contributing characteristics 51

LIST OF ABBREVIATION AND ACRONYMS

AEZ = Agro-Ecological Zone

BARI = Bangladesh Agricultural Research Institute HRC = Horticulture Research Centre

BBS = Bangladesh Bureau of Statistics

FAO = Food and Agricultural Organization of the United Nations

et al. = And others

TSP = Triple Super Phosphate

MOP = Murate of Potash

RCBD = Randomized Complete Block Design

DAT = Days after Transplanting

kg = Kilogram

SAU = Sher-e-Bangla Agricultural University SRDI = Soil Resource And Development Institute

LSD = Least Significant Difference

0C = Degree Celsius

NS = Not significant

Max = Maximum

Min = Minimum

% = Percent

NPK = Nitrogen, Phosphorus and Potassium CV% = Percentage of coefficient of variance

CHAPTER I INTRODUCTION

Tomato (Lycopersicon esculentum Mill.), a member of the family Solanaceae is one of the most popular and important vegetable crop grown in Bangladesh during rabi season. It is cultivated in almost all home gardens and also in the field due to its adaptability to wide range of soil and climate (Ahmed, 1976). It ranks next to potato and sweet potato in the world vegetable production and tops the list of canned vegetable (Choudhury, 1979). It has been originated in tropical America (Salunkhe et al., 1987) which includes Peru, Ecuador, Bolivia areas of Andes (Kallo, 1986). Tomato is popular as salad in the new state and is used to make soup, juice, ketchup, pickle, sauce, conserved puree, paste, powder and other products (Ahmed, 1976). Tomato is highly nutritious as it contains 94.1% water, 23 calories energy, 1.90 g protein, 1 g calcium, 7 mg magnesium, 1000 IU vitamin A, 31 mg vitamin C, 0.09 mg thiamin, 0.03 mg riboflavin, 0.8 mg niacin per 100 g edible portion (Rashid, 1983). Tomato has high nutritive value especially vitamin A and vitamin C. Therefore, it can be meet up some degree of vitamin A and vitamin C requirement and can contribute to solve malnutrition problem.

GA₃ is known to promote fruit development in pollinated ovaries that undergo dormancy due to high temperature (Johnson and Liverman, 1957). Fruit set in tomato can be increased by applying plant growth regulators to compensate the deficiency of natural growth substances required for its development (Singh and Choudhury, 1966). Therefore, it is necessary to find out the effective dose of growth regulators, viz. GA₃ in promoting the fruit set that will eventually lead to enhance increasing yield of tomato even in higher temperature that

prevails in the later part of the growing season under Bangladesh condition.

Pruning and training in tomato plants are practiced in certain areas of the United States, especially in some parts of the southern states and in few other regions (Thompson and Kelly, 1957). Majority of the tomato growers of Bangladesh have little knowledge about the advantage of pruning in tomato production. Usually the farmers of Bangladesh cultivate tomato without pruning and even they do not maintain proper plant density.

In Bangladesh, the statistics shows that tomato was grown in 19643 hectares of land and the total production was approximately 143,058 metric tons during the year 2007-2008 (BBS, 2008), which is very low in comparison to other countries namely, India (15.67 t/ha), Japan (52.82 t/ha) and USA (63.66 t/ha) (FAO, 1995).

The yield of tomato in our country is not satisfactory in comparison to its requirement (Aditya et al., 1999). The low yield of tomato in Bangladesh, however, is not an indication of low yielding ability of this crop, but of the fact that low yielding variety, poor crop management practices and lack of improved technologies.

Generally, tomato is cultivated in winter season in Bangladesh. There is considerable interest in extending the cultivation of tomato over a longer period.

However, high temperature before and after the short winter season inhibits the flower and fruit development, use of plant growth regulators viz. gibberellin and auxin has been reported to be very effective to overcome the problems of flower and fruit development in tomato (Adlakha and Verma, 1965; Groot et al., 1987).

Tomato plant can be severely pruned without affecting the yield (Patil et al., 1973).

Proper pruning method gives the best quality and early fruit in tomato (Lopez and Chan,

return by increasing yields and improvement of the quality of fruits (Davis and Ester, 1993).

Plant growth regulator (GA₃) and proper pruning method are important factors for successful tomato production. The combined effect of these production practices have not been defined clearly and the information in this respect is meager in Bangladesh. The present study was undertaken in view of the following objectives:

I. To study the effect of different GA₃ doses on growth and yield of tomato.

II. To determine the optimum level of pruning in order to achieve higher yield.

III. To find out the suitable combination of GA₃ doses and level of pruning for ensuring the maximum yield of tomato.

CHAPTER V

SUMMERY AND CONCLUSION

CHAPTER II

REVIEW OF LITERATURE

Tomato is one of the most important vegetable crops grown under field and greenhouse condition, which received much attention of the researchers throughout the world. Among various research works, investigations have been made in various parts of the world to determine the suitable pruning level and optimum dose of growth regulator GA₃ have marked effects on tomato production. Various investigations have been carried out for its successful cultivation. However, the combined effects of these production practices have not been defined clearly. In Bangladesh, there is a little studies on the influence of pruning or GA₃ on the growth and yield of tomato. The relevant literature on tomato and some other related crops available in this connection have been reviewed here to the present study.

2.1 Literature on GA₃

Vegetable growth regulators are capable of controlling the reproductive development, from flower differentiation until the last stages in fruit development.

In particular, fruit set and development stage depends on the endogenous content of this substance, being possible to manipulate the beginning of fruit development by external application of hormones. We have previously evaluated the fruit set and development process in tomato cultivation in the greenhouse in response to the application of beta -NOA and GA₃ in fixed doses. Differential sensitivity was observed depending on the genotype and regulator type. Studies were conducted

GA₃ as ways to improve the fruit set and development of parthenocarpic fruits.

Regulator types beta -NOA and GA₃in variable doses and application dates were considered as factors. Using unpollinated ovaries as an experimental system, it was possible to conclude that the application of 40 ppm of beta -NOA at 7 days post-anthesis would offer the best advantages from a performance point of view and a lower physiologic impact, not altering the period of fruit development (Aguero et al., 2007).

The effect of applied gibberellin (GA₃) and auxin on fruit-set and growth has been investigated by Serrani et al. (2007) in tomato (Solanum lycopersicum L.) cv Micro-Tom. It was found that to prevent competition between developing fruits only one fruit per truss should be left on the plant. Unpollinated ovaries responded to GA₃ and to different auxins [indol-3-acetic acid, naphthaleneacetic acid, and 2,4-dichlorophenoxyacetic acid (2,4-D)], 2,4-D being the most efficient.

Simultaneous application of GA₃and 2,4-D produced parthenocarpic fruits similar to pollinated fruits, but for the absence of seeds, suggesting that both kinds of hormones are involved in the induction of fruit development upon pollination. It is concluded that Micro-Tom constitutes a convenient model system, compared to tall cultivars, to investigate the hormonal regulation of fruit development in tomato.

An experiment was conducted by Rai et al. (2006) during the 2003 winter season in Meghalaya, India on tomato cv. Manileima to study the effect of plant growth regulators on yield. The treatments comprised 25 and 50 mg GA₃/litre; water spray. Data were recorded for growth, flowering and fruiting characteristics, GA₃ significantly reduced the number of seeds per fruit but increased plant height and number of branches per plant.

Khan et al. (2006) conducted an experiment to study the effect of 4 levels of gibberellic acid spray on the growth, leaf-NPK content, yield and quality parameters of 2 tomato cultivars (Lycopersicon esculentum Mill.), namely

“Hyb-SC-3” and “Hyb-Himalata”. They reported that irrespective of its concentration, spray of gibberellic acid proved beneficial for most parameters, especially in the case of “Hyb-SC-3”.

Nibhavanti et al. (2006) carried out an experiment on the effects of gibberellic acid, NAA, 4-CPA and boron at 25 or 50 ppm on the growth and yield of tomato (cv. Dhanshree) during the summer season of 2003. Plant height was greatest with gibberellic acid at 25 and 50 ppm (74.21 cm and 75.33 cm, respectively) and 4-CPA at 50 ppm (72.22 cm). The number of primary branches per plant did not significantly vary among the treatments. Gibberellic acid at 50 ppm resulted in the lowest number of primary branches per plant.

Sasaki et al. (2005) studied the effect of plant growth regulators on fruit set of tomato (Lycopersicon esculentum cv. Momotaro) under high temperature and in a field (Japan) under rain shelter. Tomato plants exposed to high temperature (34/20 degrees C) had reduced fruit set. Treatments of plant growth regulators reduced the fruit set inhibition by high temperature to some extent.

Kataoka et al. (2004) conducted an experiment on the effect of uniconazole on fruit growth in tomato cv. Severianin and reported that uniconazole (30 mg/litre) reduced fruit weight when applied to parthenocarpic fruits at approximately 0, 1 and 2 weeks after anthesis, but had no effect on fruit weight when applied at approximately 3 weeks after anthesis. To determine the antagonism between gibberellic acid (GA) and uniconazole in the regulation of fruit growth, flower clusters were treated with uniconazole ( 5 mg/L) and GA (5 or 50 mg/L). They reported that no notable gibberellin's activity was detected in treated fruits at 3 days to 4 weeks after treatment. The mean fresh weight of fruits at 4 weeks after treatment was lower than that of the control value. The results suggest that endogenous gibberellins in the early phase are important

Sun et al. (2000) reported the role of growth regulators on cold water for irrigation reduces stem elongation of plug-grown tomato seedlings. The effect of growth regulators (abscisic acid, gibberellic acid (GA), paclobutrazol, ethephon, IAA and silver thiosulfate) and cold water irrigation at different temperatures (5, 15, 25, 35, 45 and 55 ^°C) on the reduction of stein elongation of plug-grown tomato seedlings was investigated. Paclobutrazol, ethephon and GA reduced the stem length of the tomatoes at several water temperatures.

Cold water irrigation with the addition of 1.8 ppm GA or irrigation at room temperature could promote stem elongation. Irrigation at room temperature with the addition of 10 ppm paclobutrazol (GAs biosynthesis inhibitor) or cold water irrigation could inhibit stem elongation. The reduction in stem elongation in plug-grown tomato seedlings was due to the relationship of GAs metabolism and sensitivity.

El-Habbasha et al. (1999) studied the response of tomato plants to foliar spray with some growth regulators under late summer conditions. Field experiments were carried out with tomato (cv. Castelrock) over two growing seasons (1993- 94) at Shalakan, Egypt. The effects of GA₃, IAA, TPA (tolylphthalamic acid) and 4-CPA (each at 2 different concentrations) on fruit yield and quality were investigated. Many of the treatments significantly increased fruit set percentage and total fruit yield, but also the percentages of puffy and parthenocarpic fruits, compared with controls.

Tomar and Ramgiry (1997) found that plants treated with GA₃ showed significantly greater plant height, number of branches/plant, number of fruits/plant and yield than untreated controls. GA₃ treatment at the seedling stage offered valuable scope for obtaining higher commercial tomato yields.

El-Abd et al. (1995) studied the effect of plant growth regulators for improving fruit set of tomato. Two tomato cv. Alicante crops were produced in pots in the greenhouse. When the third flower of the second cluster reached anthesis,

the second cluster was sprayed with IAA, GA₃ or ABA at 10-4, 10-6 or 10-8 M each and ACC at 10-9, 10-10 or 10-11 M. All concentrations of IAA, GA₃, ACC and ABA induced early fruit set compared with controls sprayed with distilled water. GA₃ led to the formation of leafy clusters, with the number of leaves formed increasing with GA₃ concentration.

Groot et al. (1987) reported that GA was indispensable for the development of fertile flowers and for seed germination, but only stimulated in later stages of fruit and seed development.

Sumiati (1987) reported that tomato cultivars, “Gondol”, “Meneymaker”,

“Intan” and “Ratan” sprayed with 1000 ppm chlorflurenol, 100 ppm IAA, 50 ppm NAA or 10 ppm GA₃ or left untreated, compared with controls, fruit setting was hastened by 4-5 days in all cultivars following treatment with 100 ppm IAA or 10 ppm GA3 .

Leonard et al. (1983) observed that inflorescence development in tomato plants (cv. King plus) grown under a low light regime was promoted by GA applied directly on the inflorescence.

In China, Wu et al. (1983) sprayed one month old transplanted tomato plants with GA at 1, 10 or 100 ppm. They reported that GA at 100 ppm increased plant height and leaf area.

Onofeghara (1981) conducted an experiment on tomato sprayed with GA at 20- 1000 ppm and NAA at 25- 50 ppm. He observed that GA promoted flower primodia production and the number of primordia and NAA promoted flowering and fruiting.

stimulated plant growth. It reduced the total number of flowers per plant, but increased the total yield compared to the control. GA₃ also improved fruit quality.

Mehta and Mathi (1975) reported that treatments with NAA at 0.1 or 0.2 ppm improved the yield of tomato irrespective of planting date. Maximum fruit set, early and total yield, fruit number and weight were obtained in response to 4- D at 5 ppm followed by NAA at 0.2 ppm. He also reported that GA treatments at 10 or 25 ppm improved the yield of tomato cv. Pusa Ruby irrespective of planting date. GA gave earlier setting and maturity.

Kaushik et al. (1974) carried out an experiment with the application of GA₃ at 1, 10 or 100 mg/L on tomato plants at 2 leaf stage and then at weekly interval until 5 leaf stage. They reported that GA₃ increased the number and weight of fruits per plant at higher concentration.

Hossain (1974) investigated the effect of gibberellic acid along with parachlorophenoxy acetic acid on the production of tomato. He found that GA₃ applied at 50, 100 and 200 ppm produced an increased fruit set. However, GA₃ treatment induced a small size fruit production. A gradual increase in the yield per plant was obtained with higher concentration of GA_3.

Choudhury and Faruque (1972) reported that the percentage of seedless fruit increased with an increase in GA₃ concentration from 50 ppm to 100 ppm and 120 ppm. However, the fruit weight was found to decrease by GA₃effects.

Jansen (1970) reported that tomato plants treated with GA neither increased the yield nor accelerated fruit ripening. He also mentioned that increasing concentration of GA reduced both the numbers and size of the fruits.

Adlakha and Verma (1965) observed that when the first four clusters of tomato plants were sprayed three times at unspecified intervals with GA at 50 and 100

ppm, the fruit setting, fruit weight and total yield increased by 5, 35 and 23%, respectively with the higher concentration than the lower.

Adlakha and Verma (1964) sprayed GA in concentration of 50 and 100 ppm on flower cluster at anthesis and noted that the application of GA at 100 ppm could appreciably increase fruit size, weight, protein, sugar and ascorbic acid contents.

Gustafson (1960) worked with different concentration of GA and observed that when 35 and 70 ppm GA were sprayed to the flowers and flower buds of the first three clusters, percentage of fruits set increased but there was a decrease in the total weight. When only the first cluster was sprayed, the number of fruit set and the total weight per cluster was increased, but this response did not occur in subsequent clusters.

Rappaport (1960) noted that GA had no significant effect on fruit weight or size either at cool (11^°C) or warm (23⁰C) night temperatures; but it strikingly reduced fruit size at an optimal temperature (17^°C).

2.2 Literature on pruning

Ece and Darakci (2007) investigated relationships between number of stem and yield for some indeterminate tomato varieties. Two different stem applications (single and double-stem) and ten different indeterminate tomato varieties were used. Experiments were carried out at randomized blocks split plots experimental design with three replications during the years 2004-2005. Stem applications were applied in main blocks and varieties were applied in sub-plots. Plant total yield (kg per plant), total number of fruit per plant (number per plant), marketable plant weight (g) and marketable yield (t per ha) were taken into consideration.

Correlation and path analysis were carried out between marketable yield and the other plant characteristics. It was observed that plant total yield and number of

negative effects on marketable yield of tomato. Then, it was concluded that varieties with higher total yield, total number of fruit and adaptation capability should be selected and single stem application should be implemented for higher and quality marketable yield in tomato.

Replicated field trials were carried out by Muhammad and Singh (2007) at the Usmanu Danfodiyo University Fadama Teaching and Research Farm, Sokoto, during 2004/05 and 2005/06 dry seasons, to examine the effects of training and pruning on growth and yield of tomato (Lycopersicon lycopersicum Mill.) variety Roma VFN. Treatments consisted of factorial combination of two levels of training (staked and unstaked) and three levels pruning (three-stem, two-stem and unpruned) and three levels of intra-row spacing (20, 40 and 60 cm) laid out in a split-plot design replicated three times, with training allocated to the main plots and pruning intra-row spacing to the sub-plots. Results of training and pruning are presented in this paper. Results revealed that mean fruit length and diameter in the first trial, fruit weight in both trials and the two trials combined, total fresh fruit yield in the first trial and combined and percentage marketable yield in the first trial and the combined were significantly (p<0.05) higher in the tomato plants that were staked. Results on pruning showed that mean fruit length, diameter and weight in both trials were significantly higher in three-stem and two-stem pruned plants than unpruned plants. Similarly, three-stem pruned plant produced the highest total fresh fruit yield in both trials. Significant training x pruning interactions recorded, showed that the highest percentage marketable yield was at staked and pruned (both three and two-stem) plants; while two-stem with staking or no staking produced the highest mean fruit weight.

The effects of spacing (45 x 30, S₁; 60 x 30, S₂; 90 x 30, S₃; and 120 x 30 cm, S₄) and training system (single leader, T₁; double leader, T₂; and triple stem, T₃) on the performance of tomato (cv. Naveen-2000) were studied by Thakur et al, (2005) in Nauni, Solan, Himachal Pradesh, India, during 1997-98. T₁ resulted in the lowest number of days to first picking (72.10), and greatest fruit weight (84.27

g) and plant height (247.25 cm). The number of fruits per plant (19.57), yield per plant (1.20 kg) and yield/ha (505.80 quintal) were greatest under T₂. The highest ascorbic acid content (31.34 mg/100 g) and TSS [total soluble solids] (4.29 degrees Brix) were recorded for the unpruned control. S4 registered the lowest number of days to first picking (72.92), and greatest fruit weight (79.56 g), whereas S₃ recorded the highest number of fruits per plant (20.67) and yield per plant (1.25 quintal). Plant height was greatest under S₁(205.50 cm) and S₂(205.00 cm). The ascorbic acid content was highest under S₁ (31.15 mg/100 g). S₃ and S₄ gave the highest TSS (4.15 and 4.33 degrees Brix). T₃ + S₂ recorded the highest number of fruits per cluster (3.87). The number of fruits per plant was highest for plants under T₂ + S₂(22.43) and unpruned plants under S₃ (23.60). Yield per plant (1.35 kg) and per hectare (675.0 quintal), net return (201 503.45 rupees) and cost benefit ratio (1:2.94) were highest under T₂ + S₂. T₁ + S₄ gave the tallest plants (256.0 cm). Fruits of unpruned plants under S₁ had the highest ascorbic acid content (32.42 mg/100 g). TSS was highest for unpruned plants under S₃ (4.37 degrees Brix) and S₄ (4.76 degrees Brix). [1 quintal=100 kg].

Balraj and Mahesh (2005) carried out an experiment under greenhouse condition where seedlings of cherry tomato were raised in August 2002 in soilless media under greenhouse conditions and 30-day-old seedlings were transplanted on 1 September 2002 at 3 plant spacing (60 x 30, 60 x 60 and 60 x 90 cm) under drip fertigation system. Training of plants was performed in two systems, i.e. single main stem on each plant and two main stems on each plant. Plants of all treatments were trained and pruned regularly by removing the lateral branches from the leaf axils. Harvesting of fruits was started from the second week of November 2002 and continued up to the end of June 2003. A significant difference was observed between different treatments for number of fruit trusses per plant, average fruit weight and fruit yield of cherry tomato, but plant height was not influenced significantly by the different levels of plant spacing, stem

the greatest average fruit weight (10.1 g/fruit) was recorded when the crop was planted at the widest spacing with single main stem on each plant. Although, the highest fruit yield per plant (5.1 kg/plant) was obtained from plants with two main stems on each plant adjusted at the widest spacing, the highest fruit yield per ha (912.0 q/ha) was obtained when the cherry tomato plants with two main stems were grown at the closest spacing for long duration under semi-controlled greenhouse conditions of Delhi (India).

Davis and Ester (1993) found that early season yields were the highest using early pruning (when lateral shoots were 5-10 cm long) or delayed pruning (when lateral shoots were 30- 60 cm long) opposed to no pruning and in row spacing of 46 cm. Total season yields/hectare of pruning plants increased as in row spacing decreased. For unpruned plants, however, total season yields were high at all spacing. Total season yields were lower from delayed pruning plants than from unpruned plants. Unpruned plants produced low yields of fruits >72 mm diameter but their total yield was greater than those of pruning plants. Net return hectare ^-l was highest when i) plants spaced closely in row spacing were pruned early or ii) plants were spaced 46-76 cm apart and either pruned early or not prune.

Going through the above reviews, it is concluded that the different levels of GA₃ and stem pruning are important considering growth and yield. The literature reveals that the effects of different levels of GA₃ and stem pruning have not been studied well for the production of tomato under Bangladesh condition.

CHAPTER III

MATERIALS AND METHODS

This chapter deals with the materials and methods that were used in carrying out the experiment. It includes a short description of location of the experiment, characteristics of soil, climate, materials used, land preparation, manuring and fertilizing, transplanting and gap filling, stalking, after care, harvesting and collection of data.

3.1 Location of the experiment field:

The field experiment was conducted in the experimental farm of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka -1207 during the period from October 2010 to March 2011 to find out the effect of different concentration of GA₃ as plant growth regulator and pruning on the growth and yield of tomato. The location of the experimental site was at 23⁰74^{/ N} latitude and 90⁰35^{/ E}longitude with an elevation of 8.45 meter from the sea level.

3.2 Climate of the experimental area:

The climate of the experimental area was subtropical in nature. It is characterized by heavy rainfall, high temperature, high humidity and relatively long day during kharif season (April to September) and a scanty rainfall associated with moderately low temperature, low humidity and short day period during rabi season (October to March). Details of the meteorological data in respect of monthly maximum, minimum and average temperature, rainfall, relative humidity, average sunshine hours and soil temperature during the period of experiment is presented in Appendix I.

Legend

Fig. Layout of the experimental field

3.3 Soil of the experimental field:

Soil of the study site was silty clay loam in texture. The area represents the Agro- Ecological Zone of Madhupur tract (AEZ-28) with pH 5.8-6.5, ECE 25.28. The analytical data of the soil sample collected from the experimental area were determined in the Soil Resources and Development Institute (SRDI), Soil Testing Laboratory, Farmgate, Dhaka and have been presented in Appendix II.

3.4 Plant materials used:

The tomato variety "BARI Tomato-14" was used in the experiment. It was a high yielding, heat tolerant and indeterminate type variety. The seeds were collected from the Horticulture Research Centre, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur.

11.2 m m

31.5m

2 m

1.8m mm mm mm mm m

G₂P₂ G₀P₁

G₁P₁

G₂P₁

G₀P₂

G₁P₂

G₀P₃

G₁P₃

G₂P₃

G₃P₁

G₂P₃

G₁P₂

G₃P₂

G₁P₃ G₀P₁

T₈

G₃P₃

G₀P₂ G₁P₁

G₁P₁ G₀P₂

T₂

G₀P₃

T₂ G₁P₃

T₂

G₂P₃

T₂

G₀P₁

W

N

E

S Plot size: 2 m × 1.8 m Plant spacing: 60 × 40 cm Between replication: 1 m Plot to plot : 0.5 m

Factor-A: GA₃ G₀: control G₁: 80 ppm G₂: 100 ppm G₃: 120 ppm Factor-B: Pruning P₁: one stem pruning P₂: two stem pruning P₃: three stem pruning T₃: 100 kg/ha

G₂P₂

T₂

G₂P₁

T₂

G₂P₂

T₂

G₀P₃ G₁P₁

T₂

G₁P₂ G₃P₂

T2

G₃P₁

T2

G₂P₁ 1m

m

0.5m mm mm mm mm m mm m

G₃P₂

T₂

G₃P₂

T₂

G₃P₂

T₂

3.5 Raising of seedlings:

Tomato seedlings were raised in the seedbed situated on a relatively high land at Horticulture Farm of Sher-e-Bangla Agricultural University, Dhaka. The size of the seedbed was 3 m x l m. The soil was well prepared with the help of spade and made into loose friable and dried mass to obtain fine tilth. All weeds and stubbles were removed and 5 kg well rotten cowdung was applied during seedbed preparation. The seeds were sown on 25 October, 2010 and after sowing, seeds were covered with light soil to a depth of about 0.6 cm. Heptachlor 40 WP was applied @ 4 kg/ha around each seedbed as precautionary measure against ants and worm. The emergence of the seedlings took place within 5 to 6 days after sowing. Necessary shading by banana leaves was provided over the seedbed to protect the young seedlings from scorching sun or heavy rain.

Weeding, mulching and irrigation were done from time to time as and when required and no chemical fertilizer was used in the seedbed.

3.6 Treatments of the experiment:

The experiment consisted of two factors as follows:-

Factor A: It included four different doses of GA₃ (Gibberellic Acid) which are mentioned below with alphabetic symbol.

Doses of GA₃ Alphabetic symbol

0 ppm G₀

80 ppm G₁

100 ppm G₂

120 ppm G₃

Factor B: It consisted of three pruning levels which are mentioned below with

Pruning levels Alphabetic symbol

One stem pruning P₁

Two stem pruning P₂

Three stem pruning P₃

Total 12 treatment combinations were as follows:

G₀P₁ G₀P₂ G₀P₃ G₁P₁ G₁P₂ G₁P₃ G₂P₁ G₂P₂ G₂P₃ G₃P₁ G₃P₂ G₃P₃

3.7 Design of the experiment

The experiment was laid out in a Randomized Complete Block Design (RCBD) having two factors with three replications. The treatment combinations were accommodated randomly in the unit plots.

3.8 Layout of the experiment

An area of 31.5 m x 11.2 m was divided into three equal blocks. Each block consisted of 12 plots where 12 treatments were allotted randomly. There were 36 unit plots altogether in the experiment. The size of each plot was 2 m x 1.8 m. The distance between two blocks and two plots were l m and 0.5 m respectively.

3.9 Cultivation procedure:

3.9.1 Land preparation:

The soil was well prepared and good tilth was ensured for tomato crop production.

The land of the experimental field was ploughed with a power tiller. Later on the land was ploughed three times followed by laddering to obtain desirable tilth. The corners of the land were spaded and larger clods were broken into smaller pieces.

After ploughing and laddering, all the stubbles and uprooted weeds were removed.

Finally, the unit plots were prepared as 15 cm raised beds. Fifteen pits were made in each plot with in row-to-row and plant to plant spacing of 60 cm X 40 cm.

3.9.2 Manuring and Fertilizing:

Manure and fertilizers such as cowdung, urea, triple super phosphate (TSP) and muriate of potash (MOP) were applied in the experimental field as per recommendation of BARI (2004).

Manure / Fertiliz

er

Dose per hectar

e

Applied during

land prepara

tion (%)

Applied in pit a week before transpla

nting (%)

Applied as top- dressing in rows

1

^st

installme

nt at 30 DAT (%)

2

^nd

installme

nt at 60 DAT (%)

Cowdung 10 t 100 - - -

Urea 550 kg - 33.33 33.33 33.33

TSP 450 kg 100 - - -

MOP 250 kg - 33.33 33.33 33.33

The entire amount of cowdung and TSP were applied as basal during land preparation. Urea and MOP were used as pit placement and top dressing in two equal installments. First and second installments were done at 30 and 60 days after transplanting.

3.9.3 Transplanting of seedlings

Healthy and uniform 35 days old seedlings were uprooted separately from the seed bed and were transplanted in the experimental plots in the afternoon of 30 December, 2010 maintaining a spacing of 60 cm x 40 cm between the rows and plants, respectively. This allowed an accommodation of 15 plants in each plot.

The seedbed was watered before uprooting the seedlings from the seedbed so as to

Shading was provided using banana leaf sheath for three days to protect the seedling from the hot sun and removed after seedlings were established. Seedlings were also planted around the border area of the experimental plots for gap filling.

3.9.4 Preparation of GA₃

GA₃in different concentrations of 0, 80, 100 and 120 ppm were prepared following the procedure mentioned below and spraying was done during the noon using hand sprayer. 80 ppm solution of GA₃ was prepared by dissolving 80 mg of it with distilled water then distilled water was added to make the volume 1 litre 80 ppm solution in a same way 100 and 120 ppm concentration were made. An adhesive Tween-20 @0.1% was added to each solution ( Roy et al. 1991). Control plot were treated only with distilled water.

3.9.5 Intercultural operations:

After transplanting the seedlings, various kinds of intercultural operations were accomplished for better growth and development of the plants, which are as follows.

3.9.5.1 Gap filling:

When the seedlings were well established, the soil around the base of each seedling was pulverized. A few gap filling was done by healthy seedlings of the same stock where planted seedlings failed to survive.

3.9.5.2 Weeding and mulching:

Weeding was done whenever it was necessary. Mulching was also done to help in soil moisture conservation.

3.9.5.3 Stalking and pruning:

When the plants were well established, stalking was given to each plant by bamboo sticks to keep them erect. Within a few days of stalking, as the plants grew up,

the first pruning was done when the plant gave three branches and it was observed at 35 days after transplanting. The second pruning was done at 45 days after transplanting.

3.9.5.4 Application of GA₃

Application of GA3 was done at 20 and 30 days after transplanting as per treatment.

3.9.5.5 Irrigation:

Light watering was given with wateringcan immediately after transplanting the seedlings and then flood irrigation was done as and when necessary throughout the growing period upto harvest.

3.9.4.5 Plant protection:

Insect pests: Melathion 57 EC was applied @ 2 ml/l of water against the insect pests like cut worm, leaf hopper, fruit borer and others. The insecticide application was made fortnightly after transplanting and stopped before second week of first harvest. Furadan lO G was also applied during final land preparation as soil insecticide.

Disease: During foggy weather precautionary measure against disease attack of tomato was taken by spraying Diathane M-45 fortnightly @ 2 g/l of water, at the early vegetative stage. Ridomil gold was also applied @ 2 g/l of water against blight disease of tomato.

3.9.4.6 Harvesting:

Fruits were harvested at 3 days interval during early ripe stage when they developed slightly red color. Harvesting was started from 15 February, 2011 and was continued up to 30 April, 2011.

data of root from each plot and mean data on the following parameters were recorded:- Plant height

Number of leaves per plant Number of branches per plant Number of clusters per plant Number of flowers per plant Number of fruits per plant Length of fruit

Diameter of fruit

Dry matter content of leaves Dry matter content of fruits Yield per plot

Yield per hectare

3.11 Data collection:

Five plants were selected randomly from each plot for data collection in such a way that the border effect could be avoided for the highest precision. Data on the following parameters were recorded from the sample plants during the course of experiment.

Plant height:

Plant height at 30, 45, 60, 75 and 90 DAT was measured from sample plants in centimeter from the ground level to the tip of the longest stem and the mean value for each treatment was calculated. Plant height was also recorded at 15 days interval starting from 30 days of transplanting upto 90 days to observe the growth rate of plants.

Number of leaves per plant:

The number of leaves of the sample plants was counted at 45 DAT, 60 DAT, 75 DAT and 90 DAT and the average number of leaves produced per plant was recorded.

Number of branches per plant:

The number of branches of the sample plants was counted at 45 and 60 DAT and the average number of branches produced per plant was recorded.

Number of clusters per plant:

The number of fruit clusters was counted from the sample plants and the average number of clusters borne per plant was recorded at the time of final harvest.

Number of flowers per plant:

Total number of flowers was counted from selected plants and their average was taken as the number of flowers per plant.

Number of fruits per plant:

Total number of fruits was counted from selected plants and their average was taken as the number of fruits per plant.

Length of fruit:

The length of fruit was measured with slide-calipers from the neck to the bottom of 10 selected marketable fruits from each plot and their average was taken in cm as the length of fruit.

Fruit diameter:

Diameter of fruit was measured at the middle portion of 10 selected marketable fruit from each plot with slide-calipers and their average was taken in cm as the diameter of fruit.

Dry matter content of leaves was measured after last harvesting harvesting from randomly selected 100 g of leaf samples previously sliced into very thin pieces were put into envelop and placed in oven at 60^°C for 72 hrs. The sample was then transferred into desiccators and allowed to cool down to the room temperature. The final weight of each sample was taken. The dry matter was calculated by the following formula:

Dry weight of the sample

Dry matter content of leaves (%) = X 100

Fresh weight of the sample

Dry matter content of fruits

Immediately after harvest, a sample of 100 g fruits was taken randomly and cut into small pieces. The small pieces were sun dried for 3 days and then oven dried for 72 hours at 70 to 80 ^oC taken into envelope until constant weight. The sample was then transferred into desiccators and allowed to cool down to the room temperature. The final weight of each sample was taken. The dry matter content of sample was calculated by the following formula:

Constant dry matter of fruits

Dry matter content of fruit(%) = X 100

Fresh weight of fruits

Yield per plot:

A balance was used to record the harvested fruits from 5 randomly selected plants and expressed in kilogram. It was measured by the following formula:

Yield per plot = Yield of single plant x 15

Yield per hectare:

From the yield per plot, yield per hectare was calculated.

3.12 Statistical analysis:

The data in respect of growth and yield components were statistically analyzed to find out the significance of the experimental results. The means of all the treatments were calculated and the analysis of variance for each of the characters under study was performed by F test. The difference among the treatment means was evaluated by Least Significant Difference (LSD) at 5% level of probability (Gomez and Gomez, 1984).

CHAPTER IV

RESULTS AND DISCUSSION

The present study was conducted to find out the effect of GA₃ and pruning on growth and yield of tomato. Data on different growth and yield contributing characters were recorded to find out the optimum dose of GA₃ and optimum pruning type for “BARI Tomato-14”. The analysis of variance (ANOVA) of the data on different growth and yield components are given in Appendix III-IV. The results have been presented and discussed, and possible interpretations have been drawn under the following headings.

4.1 Plant height

Plant height varied significantly at different days after transplanting (DAT) for different doses of GA₃ (Appendix III). At 30 DAT, the maximum plant height (55.78 cm) was obtained from G₃(120 ppm GA₃), while the minimum (47.83 cm) was recorded from G₀ (0 ppm GA₃). The maximum plant height (70.44 cm) was found from G₃ and the minimum (56.84 cm) was obtained from G₀ at 45 DAT (Fig. 1). At 60 DAT, the maximum plant height (102.80 cm) was obtained for G₃ (120 ppm GA₃), while the minimum (88.56 cm) was recorded for G₀ (0 ppm GA₃). The maximum plant height (117.30 cm) was observed in G₃ and the minimum (95.67 cm) was found from G₀ at 75 DAT (Fig. 1). The effect of GA₃ application on plant height was best at the concentration of 120 ppm which was followed by 100, 80 and 0 ppm (Fig. 1). Rai et al. (2006) and Nibhabanti et al.

(2006) observed that GA₃ increased plant height at 25 and 50 ppm. Wu et al.

(1983) reported that GA₃ at 100 ppm increased plant height.

Due to pruning plant height showed significant variation at different days after transplanting (DAT) (Appendix III). The maximum plant height (55.17 cm) was

observed in P₂ (2 stem pruning) and the minimum (49.33 cm) was found from P₁ (1 stem pruning) which was statistically similar to P₃ (3 stem pruning) at 30 DAT.

At 45 DAT, the maximum plant height (67.75 cm) was obtained for P₂, while the minimum (61.77 cm) was recorded for P_1, which was statistically similar to P₃ (62.12 cm) (Fig. 2). The maximum plant height (101.00 cm) was observed for P₂ (2 stem pruning) and the minimum (90.42 cm) was found for P₁ at 60 DAT (Fig.

2). At 75 DAT the maximum plant height (113.60 cm) was obtained for P₂, while the minimum (101.30 cm) was recorded for P₁(Fig. 2).

Fig.1. Effect of GA3on plant height of tomato

The variation was found due to combined effect of GA₃ application and pruning on plant height at different DAT. The maximum plant height (61.00 cm) was recorded from the treatment combination G₃P₂ (2 stem pruning with GA₃ application at 120 ppm), while the treatment combination of G₀P₁ (1 stem pruning with no GA₃ application) gave the minimum (46.33 cm) plant height, which was statistically similar to G₁P₁, G₀P₂, G₀P_3,G₁P₃, G₂P₃ and G₂P₁ (Table 1) at 30 DAT.

At 45 DAT the treatment combination of G₃P₂ produced the tallest (76.00 cm) plant where as the shortest plant (54.23 cm) was performed by the treatment of combination G₀P_1.The maximum plant height (108.70 cm) was obtained from the